This case-control study will investigate the association of lower urinary tract cancer with chenical mutagens in the urine in two ethnically-distinct groups in Hawaii which have different levels of risk for this disease (high risk for Caucasians and intermediate risk for Japanese). It will also include data on the association of this cancer with smoking cigarettes, drinking coffee, occupational exposures and the use of artificial sweeteners. Lower urinary tract cancer cases will be identified in the seven major civilian hospitals on Oahu for a period of five years (approximately 104 Caucasian and 92 Japanese cases). We will also recruit surviving prevalent cases who were diagnosed within two years of the start of the study (30 Caucasian and 27 Japanese cases). For each case, two neighborhood controls matched by race, sex and age within five years will be selected and interviewed. Over-night urine samples for a battery of mutagen tests (Ames) will be collected from all subjects. The questionnaires and format for this study will be similar in design to an ongoing case-control study being conducted by the Harvard School of Public Health in three different populations (including the low risk Japanese in Nagoya, Japan). By this arrangement, we will be able to compare the findings between the Japanese in Hawaii and Nagoya in an attempt to identify factors which account for the increase in lower urinary tract cancer among the Japanese in Hawaii. In addition, we will compare data of the Caucasians and Japanese in Hawaii to identify factors which may account for the difference in risk between these two groups which reside on the same island.